- [alpha] Pods now have alpha support for setting whitelisted, safe sysctls. Unsafe sysctls can be whitelisted on the kubelet. ([docs](http://kubernetes.io/docs/admin/sysctls/)) ([kubernetes/features#34](https://github.com/kubernetes/enhancements/issues/34))

* The Sysctls experimental feature has been promoted to beta (enabled by default via the `Sysctls` feature flag). PodSecurityPolicy and Pod objects now have fields for specifying and controlling sysctls. Alpha sysctl annotations will be ignored by 1.11+ kubelets. All alpha sysctl annotations in existing deployments must be converted to API fields to be effective. ([#6371](https://github.com...

  and “net.ipv4.tcp_keepalive_probes“ sysctl by default; Pod Security Admission
  allows this sysctl in `v1.29+` versions of the baseline and restricted policies. ([#121240](https://github.com/kubernetes/kubernetes/pull/121240), [@HirazawaUi](https://github.com/HirazawaUi))
- `kubelet` now allows pods to use the `net.ipv4.tcp_keepalive_time` sysctl by default

* The `spec.SecurityContext.Sysctls` field is now dropped during creation of `Pod` objects unless the `Sysctls` feature gate is enabled. ([#72752](https://github.com/kubernetes/kubernetes/pull/72752), [@rajathagasthya](https://github.com/rajathagasthya))
    * The `spec.AllowedUnsafeSysctls` and `spec.ForbiddenSysctls` fields are now dropped during creation of `PodSecurityPolicy` objects unless the `Sysctls` feature gate is enabled.

- Introduced the flag `--ipvs-strict-arp` to configure stricter ARP sysctls, defaulting to false to preserve existing behaviors. This was enabled by default in 1.13.0, which impacted a few CNI plugins. ([#75295](https://github.com/kubernetes/kubernetes/pull/75295), [@lbernail](https://github.com/lbernail))

- Pod SecurityContext sysctls name parameter for update requests where the existing object's sysctl contains slashes and kubelet sysctl whitelist support contains slashes. ([#102393](https://github.com/kubernetes/kubernetes/pull/102393), [@mengjiao-liu](https://github.com/mengjiao-liu)) [SIG Apps, Auth, Node, Storage and Testing]...

          _MINIO_LDAP_TEST_SERVER: ${{ matrix.ldap }}
          _MINIO_ETCD_TEST_SERVER: ${{ matrix.etcd }}
          _MINIO_OPENID_TEST_SERVER: ${{ matrix.openid }}
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0
          make test-iam
      - name: Test with multiple OpenID providers
        if: matrix.openid == 'http://127.0.0.1:5556/dex'
        env:

- Sysctls graduates to General Availability and thus unconditionally enabled. ([#99158](https://github.com/kubernetes/kubernetes/pull/99158), [@wgahnagl](https://github.com/wgahnagl))

        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0
          make test-pbac

      - name: Test Config File
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0
          make test-configfile

      - name: Test Replication
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0

          GO111MODULE: on
          MINIO_KMS_SECRET_KEY: "my-minio-key:OSMM+vkKUTCvQs9YL/CVMIMt43HFhkUpqJxTmGl6rYw="
          MINIO_KMS_AUTO_ENCRYPTION: on
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0
          make verify